javascript - Check whether a string matches a regex in JS

You can use match() as
well:

if
            (str.match(/^([a-z0-9]{5,})$/)) {

            alert("match!");
}

But
test() seems to be faster as you can read href="https://stackoverflow.com/a/10940138/1895428">here.

Important
difference between match() and
test():

match()
works only with strings, but test() works also with
integers.

12345.match(/^([a-z0-9]{5,})$/);
            // ERROR
/^([a-z0-9]{5,})$/.test(12345); //
            true
/^([a-z0-9]{5,})$/.test(null); //
            false


// Better watch out for undefined
            values
/^([a-z0-9]{5,})$/.test(undefined); //
            true